Upgrading computers can save you considerable money versus buying new; these days, high-performance processors and motherboards are relatively cheap, and you save even more money if you install the components yourself. Installing a new motherboard is not difficult, but it does require planning and attention to detail. One of the most important tasks when installing a motherboard is to mount standoffs properly to ensure that the metal case does not contact or short out the motherboard.

Common Types of Standoffs

Generally speaking, there are two common types of standoffs for motherboards: metal and plastic. Metal standoffs are usually hexagonal in shape and screw into the base plate of the computer case. Metal standoffs also contain a hollow, threaded cavity in which you insert screws to secure the motherboard to the case base plate. Conversely, plastic standoffs server to elevate the motherboard only and do not secure the board to the base plate. Plastic standoffs are usually flat on the bottom (the part that touches the base plate) and pointed at the top. The pointed top end of a plastic standoff compresses slightly so that you can push it through a mounting hole on the motherboard. After you release the compressed top point of a plastic standoff, it expands and locks, securing the motherboard to the base plate.

Proprietary Standoffs

The aforementioned types of standoffs ship with about 95 percent of computer cases. However, some esoteric or high-end cases may include proprietary metal standoffs with clips for securing them to the base plate. With a few cases, you may find plastic standoffs with pointed tips and screw-like bottoms for securing them to the base plate. Even if your case does ship with proprietary standoffs, installing and using them is essentially the same as when working with the more common ones. In most cases, standoffs ship with the computer case and not the motherboard. Therefore, if you lose proprietary standoffs, replacing them may be a bit difficult. Usually, though, you can use standard plastic standoffs to replace proprietary ones if you're missing only one or two pieces.

ATX Form Factor Motherboards

A motherboard's form factor determines several important aspects of its compatibility with a case. Different form factors may require different types of cases in certain situations. However, most desktop motherboards use either the ATX, Mini-ATX or microATX form factor. The layout for standoffs on ATX-based form factors is generally the same. However, Mini-ATX and microATX motherboards -- as their names imply -- are smaller than standard ATX versions. Therefore, they usually contain fewer mounting holes for standoffs. With larger ATX boards, it's common to install metal standoffs near the rear edge and in the center, while using plastics standoffs near the edge closet to the front of the case. Because Mini-ATX and microATX motherboards are much smaller, they usually require no plastic standoffs for elevation of the inner edge of the board. Nevertheless, installation and placement of the metal standoffs for ATX-based motherboards is essentially the same.

Other Form Factors

Unless you're building a specialty computer or rebuilding a legacy system, you'll probably use an ATX motherboard. However, if you're building a very small box for installation in a car or other tight space, you may purchase a specialty motherboard based on a FlexATX, LPX, Mini LPX or NLX form factor. Standoff placement varies enough from more common ATX-based form factors that motherboards using one of the specialty form factors usually require an enclosure or case with a specific standoff layout. The same applies to older legacy motherboards based on the older AT form factor, which many integrators used in systems produced in the 1990s. In some rare cases, you may find newer cases that support both AT and ATX-based form factors, which was common in cases built in the late 1990s and early 2000s. However, as AT motherboards become harder to find, most case manufacturers stopped including AT standoff layouts in their case base plates. Even though standoff layouts vary with older and specialty form factors, installation is the same as it is with ATX motherboards.

Creating a Template

Before you start connecting the metal standoffs to the case base plate, take a large piece of paper and place it underneath the motherboard so you can mark the installation holes. After laying the motherboard on the piece of paper, use a pencil to color in dots at the location of all standoff holes. After coloring in the dots, remove the motherboard and push through the dots to create small holes in the paper. You can then align the paper with the holes in the base plate. Look for the hole in the upper right corner of the base plate (usually just beneath the power supply) with the label representing the form factor of your motherboard (e.g. ATX or Mini-ATX). Align the hole in the upper right corner of the paper with the appropriate hole on the base plate. After you align the holes in the upper right corner, you will be able to see where you need to install other metal standoffs.

Installing the Standoffs

For holes on the outer edge of the paper, there may be no matching holes on the base plate. For these holes on the motherboard, just insert plastic standoffs. For the other holes, insert metal standoffs into the holes on the base plate, screw them in hand tight and then use an appropriately sized nut driver to tighten them another half turn or so until secure. If you don’t have a nut driver, you can use a pair of pliers, but if you do so try not to strip the sides and avoid over-tightening -- if you apply too much pressure when tightening a standoff it may break or you may strip out the hole on the base plate.

Securing the Motherboard

Once you install all of the standoffs, align your motherboard and secure it. When placing the motherboard on top of the standoffs, do so carefully and slowly. Also, grip the motherboard on the edges and avoid touching any of the solder points on the bottom. Align the hole in the upper right corner of the motherboard with the corresponding standoff first and then rotate the board slowly until the other holes align. Insert the standoff screws that shipped with the case into the standoffs themselves and then use a Philips screwdriver to tighten them. The standoff screws look nearly identical to ones used to secure optical drives and hard drives in their bays. Therefore, ensure that you use the right screws to secure the motherboard to the base plate. If a screw spins freely in the standoff or is difficult to tighten, it is the wrong size and type.

About the Author

Jeff Grundy has been writing computer-related articles and tutorials since 1995. Since that time, Grundy has written many guides to using various applications that are published on numerous how-to and tutorial sites. Born and raised in South Georgia, Grundy holds a Master of Science degree in mathematics from the Georgia Institute of Technology.